Sulphur-bridged phenolic antioxidants
CA 2021225 A1 · Owner: Liesen, Gregory Peter · Inventors: Liesen, Gregory Peter; Lam, William Yuk-Lun
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Case EI-6004, SULFUR-BRIDGED PHENOLIC ANTIOXIDANTS Abstract, A liquid, sulfur-bridged, hindered phenol antioxidant composition is prepared by reacting a mixture of hindered phenols with a sulfur chloride in the presence of a polar modifier. The composition is an effective antioxidant in lubricating oils without causing excessive copper corrosion.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed July 16, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 16, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 16, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.